Metar

A PHP 8.4 METAR weather report parser. Parses raw METAR strings into structured, readonly value objects with full remark support and human-readable labels.

Installation

composer require jamesmorrison/metar

Requires PHP 8.4 or higher.

Usage

use JamesMorrison\Metar\Parser;

$metar = new Parser('METAR EGLL 141250Z 24015G25KT 9999 FEW040CB 12/08 Q1015 NOSIG');

Accessing Components

Every component is a readonly value object with typed properties and a label() method:

$metar->station->icao;               // 'EGLL'
$metar->observationTime->day;        // 14
$metar->observationTime->hour;       // 12
$metar->observationTime->minute;     // 50

$metar->wind->direction;             // 240
$metar->wind->speed;                 // 15
$metar->wind->gusts;                 // 25
$metar->wind->unit;                  // WindUnit::Knots
$metar->wind->speedKnots;            // 15.0
$metar->wind->speedMps;              // 7.7

$metar->visibility->distance;        // 9999.0
$metar->visibility->unit;            // VisibilityUnit::Metres

$metar->clouds[0]->amount;           // CloudAmount::Few
$metar->clouds[0]->height;           // 4000
$metar->clouds[0]->type;             // CloudType::Cumulonimbus

$metar->temperature->temperature;    // 12
$metar->temperature->dewpoint;       // 8

$metar->pressure->hectopascals;      // 1015.0
$metar->pressure->inchesOfMercury;   // 29.97

Human-Readable Labels

All components implement Labelable and Stringable:

$metar->wind->label();       // 'Wind from 240 degrees at 15 knots gusting 25 knots'
$metar->pressure->label();   // '1015 hPa / 29.97 inHg'
echo $metar->temperature;    // 'Temperature 12°C (54°F), dewpoint 8°C (46°F)'

// Full METAR summary
echo $metar->label();

JSON Serialization

The parser implements JsonSerializable:

json_encode($metar, JSON_PRETTY_PRINT);

CAVOK

When CAVOK is reported, visibility/weather/clouds are not parsed:

$metar = new Parser('METAR EGLL 141250Z 24015KT CAVOK 12/08 Q1015');
$metar->cavok; // true

Parsed Components

Property	Type	Description
station	?Station	ICAO station identifier
observationTime	?ObservationTime	Day, hour, and minute (UTC)
modifiers	Modifier[]	AUTO, COR, etc.
wind	?Wind	Direction, speed, gusts, unit (with dual-unit conversions)
windVariation	?WindVariation	Variable wind direction range
visibility	?Visibility	Prevailing visibility (with dual-unit conversions)
directionalVisibility	DirectionalVisibility[]	Sector-specific visibility
runwayVisualRange	RunwayVisualRange[]	RVR per runway
weather	Weather[]	Present weather phenomena
clouds	Cloud[]	Cloud layers
temperature	?Temperature	Temperature and dewpoint (Celsius + Fahrenheit)
pressure	?Pressure	Altimeter setting (hPa + inHg)
windShear	?WindShear	Wind shear warnings
recentWeather	RecentWeather[]	Recent weather phenomena
trends	Trend[]	NOSIG, TEMPO, BECMG trends
remarks	?Remarks	Decoded remark groups
cavok	bool	Ceiling and visibility OK

Remarks

The parser decodes 25+ remark types including:

• Station type (AO1/AO2)
• Sea-level pressure
• Peak wind and wind shift
• Hourly temperature / temperature extremes
• Pressure tendency and rapid pressure change
• Precipitation (hourly, 3/6-hour, 24-hour)
• Lightning (frequency, type, direction)
• Weather events (beginning/ending times)
• Variable ceiling and visibility
• Significant clouds (CB, TCU, ACC, etc.)
• Virga, obscurations, snow depth/increase
• Sensor status and maintenance indicators

$metar = new Parser('METAR KJFK 141250Z 24015KT 10SM FEW040 12/08 A2997 RMK AO2 SLP153 T01170083');

foreach ($metar->remarks->groups as $remark) {
    echo $remark->label() . "\n";
}

Testing

composer pest      # Run tests
composer analyse   # PHPStan (max level)
composer pint      # Code style
composer test      # All of the above

License

MIT